Pouch forming machine with vertical jaw adjustment mechanism

ABSTRACT

An adjustment mechanism for the vertical jaws of a vertical form, fill, seal pouch machine includes a frame having a track for supporting a cross arm and a pair of drive wheels turning a cross rod which rotates a drive rod to move the support bar for the vertical jaws to and away from a forming tube of the machine. A similar mechanism moves a support device for a die cutter forming a hanger hole on the pouch to and away from the forming tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of U.S. Provisional Application62/073,068 filed Oct. 31, 2014, the contents of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The invention relates to a vertical form, fill, seal machine forflexible pouches. More particularly, the invention relates to anadjustment mechanism for the vertical jaws of the machine.

BACKGROUND OF THE INVENTION

Standup flexible pouches are also known as Doypacks. These pouches areformed of a flexible film on machines such as a vertical form, fill, andseal machine. The film may be a single layer of suitable plastic butmore typically a laminate of plastics and/or foil. A sheet of film ispulled over a plow and around a forming tube, so that side edges of thesheet meet in front of the forming tube. Vertical heat seal bars sealthe side edges together to form a sleeve. The vertical seal formedbecomes the top of the pouch. A die cutter is used to form a hanginghole or euro hole in the vertical seal. A horizontal seal is placedacross the sleeve to form a bottom edge seal. It is frequently necessaryto adjust the distance between the vertical jaws and forming tubebecause of stretching or variance in the film. If the film hasstretched, the seal bars will not place the seal inwardly from the edgesresulting in an unacceptable package. In the past, this operation hasrequired the machine to stop and the adjustment is made beforerestarting the machine.

SUMMARY OF THE INVENTION

Disclosed is an adjustment mechanism for vertical jaws of a pouchforming machine. The adjustment mechanism includes a drive rod and across rod mounted to a frame. The rods are rotated by a drive mechanismto move a support arm to and away from a forming tube. In the preferredembodiment the drive mechanism is a pair of hand wheels. The support armcarries a pair of vertical jaws which have heat seal bars to seal edgesof a film together to form a sleeve of laminate material. The machinemay include an adjustment mechanism for a die cutter which forms a hanghole in the vertical seal. The adjustment mechanism includes a seconddrive rod and a second cross rod which are rotated to drive a supportarm for an adjustment mechanism for the hole cutter along the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a machine for forming flexible pouchesaccording to the invention;

FIG. 2 is a partial perspective view of the machine showing a film inposition around a formed tube;

FIG. 3 is a perspective view of the adjustment mechanism for thevertical jaws and for the die cutter taken from the rear;

FIG. 4 is a perspective view of the adjustment mechanisms for thevertical jaws and for the die cutter taken from the front;

FIG. 5 is a cross-sectional view of a cross bar, drive wheels, and driverod taken along section lines 5-5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Shown in the drawings is a vertical form, fill, and seal pouch machine10 which includes a novel adjustment mechanism 31 for easy and preciseadjustment of vertical jaws which form a vertical seal during a pouchforming operation. The adjustment may be made while the machine isoperating. The machine also includes an adjustment mechanism 100 for adie cutter for forming a hanger hole in the vertical seal. The machinemay be used to form zipper pouches or standup pouches.

As shown in FIGS. 1 and 2, the vertical form, fill, and seal machine 10includes a housing 12. A sheet of film 14 is fed into the machine 10from a roll 16. As shown in FIG. 2, the film is fed through a series ofrollers (not shown) to the machine wherein it is guided over a roller 18and over a plow 20 and around a forming tube 22. The forming tube 22extends vertically from a top of the machine towards a bottom. Theforming tube 22 has a curved rear surface 24, front surface 26, and apair of parallel sides 28. The film has a pair of side edges 30 whichafter leaving the plow are pulled together around the forming tube andpositioned between a pair of seal bars 32 carried by vertical jaws 34. Aheat unit 36 is mounted to the vertical jaws 34 to heat the film forsealing. Alternatively, the seal bars may have heating elements.

As shown in FIG. 3, a pneumatic actuator 98 moves the vertical jaws 34and the seal bars 32 together to seal the side edges 30 together to forma sleeve 36 with a vertical seal 38. If a zipper 40 is added, the zipperis fed from a reel 42 over a roller 44 at the top of the machine 10 anddown between the edges 30 of the film and the seal bars 32. It should beunderstood that the pouch 46 is formed sideways with the bottom of thepouch extending around the back of the forming tube and the verticalseal becomes the top of the pouch. Near the bottom of the machinehorizontal jaws 48 move seal bars 50 to form a seal. Product is thenfilled from a fill tube 52 into the sleeve above the horizontal sleeve.The pouch is moved downwardly by a belt mechanism 54 and anotherhorizontal seal is placed on the sleeve. The horizontal seal is severedthrough the middle by a cutter (not shown) and a sealed filled pouchdrops to a conveyor 56 below.

The adjustment mechanism 31 for the vertical jaws 34 is best shown inFIGS. 3-4. The adjustment mechanism 31 for the vertical jaws includes aframe 60 supporting an upper pair of tracks 62. The frame 60 is mountedto one side of the housing 12. A support arm 66 extends perpendicularlyfrom the frame 60. The support arm 66 has a carriage 63 with a pair ofcars 68 which ride along the upper pair of tracks 62. The cars 68 have asmooth bearing-like surface such as Delrin. A drive mechanism moves thesupport arm to and away from the front of the forming tube to adjust forstretching in the film. The drive mechanism includes a first drive rod70 which has a threaded portion 72 at one end. The threaded portion 72is received in a nut 76 having internal threads mounted to the supportbar. The other end 78 of the drive rod 70 is received into a box 80mounted to the frame 60.

As best shown in FIG. 5, the box 80 has a bearing 82 in one side 84 torotatably support the drive rod 70. A cross rod 86 passes through twoother sides 88 of the box. A bevel gear 90 is mounted on the end of thedrive rod 70 to engage a bevel gear 92 on the cross rod 86 to permit thecross rod 86 to rotate the drive rod 70. This in turn moves the supportarm 66 by way of the nut 76 along the upper tracks 62. A pair of handwheels 94, 96 are mounted to either end of the cross rod 86. One of thehand wheels 94 is on an interior portion 95 of the housing and the otherhand wheel 96 is disposed such that it is on the exterior of thehousing. Locking mandrels 98 are also provided on the wheel boxes suchthat the position of the jaws may be locked merely by moving a lever tosqueeze a brake surface inwardly against the cross rod.

Thus, rotation of one of the hand wheels 94, 96 rotates the cross rod 86to drive the drive rod 70 to adjust the support arm 66 and jaws 34 toand away from the forming tube 22. In this way the position of thevertical seal 38 can be precisely and easily changed when the filmbecomes stretched or distorted as it moves through the machine 10. Theoperator can adjust the position of the jaws 34 by moving the hand wheel94 from the exterior of the housing without stopping the machine.

The adjustment device 100 for the hanger hole punch die cutter 58 ismounted to the second set of rails 64. A second support arm 99 carries avertical adjustment mechanism 101 for the die cutter. Like the supportarm 66 of vertical jaw adjustment mechanism 31, the support arm 99 has acarriage 103 with a pair of cars 102 to slide on the second set of rails64. The drive rod 106 and cross rod 108 are provided as well as a secondset of hand wheels 110, 112 to adjust the position of the support armalong a horizontal plane inwardly and outwardly with respect to theforming tube 28. A box 105 with bevel gears (not shown) is alsoprovided. The vertical adjustment mechanism 101 includes an upper arm114 and lower bar 116 which are connected by a pair of tubes 118. Asupport bar 120 has bores 122 which ride up and down along the tubes118. A screw rod 124 is mounted between the tubes to pass through thesupport bar 120. The support bar 120 has a threaded nut 124 to receivethe threads 126 of the screw rod 124. A hand wheel 128 is mounted to thetop of the screw rod 124 to rotate the tube to adjust the position ofthe second support arm upwardly and downwardly. A brake mandrel 126 ispositioned above the second support arm and a lever rotates to advance abrake surface against the drive rod to prevent rotation once thevertical height is established.

At the distal end of the support bar 120 is a pneumatically driven diecutter 58 or hole punch. The hole punch punches a hole in the verticalseam 38 of the sleeve 22 to act as a hanging hole 130 for the pouch 46once it is formed (FIG. 1). Thus, the die cutter adjustment mechanismoperates in a similar fashion to the vertical jaw adjustment mechanismto move the die cutter assembly inwardly and outwardly with respect tothe forming tube along a horizontal axis to properly position the hangerhole.

As an alternative to the drive wheels, a servomotor may be mounted tothe frame to turn the drive rods to make the adjustment. The servomotormay be controlled by a control box to drive the motor in one directionor the other to adjust the positions of the support arm.

Thus is disclosed a novel adjustment mechanism for the vertical jaws andhanger hole die punch to readily adjust these mechanisms.

It will be understood that variations of the disclosure are within thescope and spirit of the invention as defined by the appended claims.

1. A machine for forming a pouch, the machine comprising: a housing; aforming tube, the forming tube being generally horizontally alignedwithin the housing; a frame mounted to the housing; a first drive rodpivotally mounted to the frame, the first drive rod having a threadedportion; a first support bar movably mounted to the frame, the firstsupport bar having a portion threadably engaging the threaded portion ofthe drive rod; a set of vertical jaws having seal bars mounted to thesupport bar; a device for rotating the first rod so as to move the firstsupport bar and seal bar to and away from the forming tube.
 2. Themachine of claim 1 wherein the first support bar has a nut portion inengagement with the threaded portion of the first drive rod.
 3. Themachine of claim 1 wherein the device for rotating the drive rod is atleast one rotating member connected to a first cross rod having a bevelgear in engagement with the first rod.
 4. The machine of claim 3 whereinthe at least one rotating member is a pair of wheels, one of the pair ofwheels mounted to the shaft outside of the housing and the other wheelof the pair of wheels mounted to the shaft on the inside of the housing.5. The machine of claim 1 further comprising a die cutter mounted to asecond support bar, the second support bar slidably mounted to theframe.
 6. The machine of claim 5 further comprising a vertical liftmechanism for moving the die cutter along a vertical axis.
 7. Themachine of claim 6 wherein the machine further comprises a second driveshaft for rotatably moving the second support arm.
 8. The machine ofclaim 7 wherein the machine further comprises a second cross rod inengagement with the second drive rod to move the second support arm toand away from the forming tube.